1. Field of the Invention
The present invention has for its object to prevent the contagion of infectious diseases during dental impression-taking, and relates to an antiseptic-containing alginate impression material intended to eliminate the contagion of infectious diseases from counter-dies of impression materials by previously incorporating a specific amount of an antiseptic innoxious to the human body into the powders of alginate impression materials.
2. Statement of the Prior Art
During dental examination and treatment, dentists or dental technicians may often catch pathogenic bacteria or viruses via the blood or sputum of a patient suffering from an infectious disease. For that reason, they wear protecting gloves, masks, caps and glasses during dental examination and treatment, thereby preventing a direct contact of the patient's blood or sputum with them. It is also common sense with them to sterilize dental instruments contaminated with the blood or sputum of a patient suffering from an infectious disease by the application of heat or chemicals.
For a patient suffering from an infectious disease, a handpiece in place of a turbine is used to prevent splattering of cuttings, blood or sputum, and an antiseptic is discharged to a vacuum arrangement and a discharge system so as to attempt preventing contamination.
Although it is preventable for dentists, dental technicians or other patients to catch direct infection from infectious diseases, as mentioned above, yet pathogenic bacteria or viruses carried by blood or sputum remain deposited onto the counter-die of an impression material taken out of the mouth of an infected patient. When gypsum is cast in the counter-die of the impression material, onto which pathogenic bacteria or viruses remain deposited, in making a gypsum model, such bacteria or viruses are carried onto the surface of the gypsum model. Thus, dental technicians manipulate the gypsum model infected by pathogenic bacteria or viruses, touching them all the while.
This further leads to a fear that such pathogenic bacteria or viruses may be carried in the body system through a wound in the hand or foodstuffs taken in by way of an infected hand. It is understood that with a view to preventing the contagion of an infectious disease through such an impression material, the counter-dies thereof are usually disinfected by chemicals, as mentioned just below.
The counter-die of an impression material is first well washed with water, and is then immersed in an about 1 to 5% aqueous solution of sodium hypochlorite for about 10 to 30 minutes. Since sodium hypochlorite is a very unstable substance, however, such solutions should all be prepared every day and done away with after use.
In some cases, use may be made of formaldehyde. After washing with water, a counter-die is dipped in an about 3 to 8% aqueous solution of formaldehyde or an 8% solution of formaldehyde in 70% of an alcohol for about 10 to 30 minutes. Still alternatively, the counter-die of an impression material may be dipped in an aqueous solution of glutaraldehyde or an iodine compound for about 10 to 30 minutes. Still alternatively, the counter-die of an impression material may be sprayed with an about 1 to 5% aqueous solution of sodium hypochlorite or an about 1 to 5% aqueous solution of an iodine compound by means of spray equipment filled therewith.
With regard to the methods involving immersion of the counter-die of an impression material having pathogenic bacteria or viruses deposited thereonto in an antiseptic solution for about 10 to 30 minutes for the purpose of killing off such bacteria or viruses, there are some disadvantages, as stated below.
(1) The operation of disinfecting the counter-die of an impression material by immersing it in an antiseptic solution tends to slip from memory or be omitted through inadvertence, since it is not included in the essential steps of preparing a gypsum model by casting gypsum on the counter-die. PA1 (2) Since the operation of immersing the counter-die of an impression material in an antiseptic solution for about 10 to 30 minutes is reluctant to carry out, a general tendency is that the counter-die of an impression material is only washed with water, while its immersion in an antiseptic solution is left undone. Thus, it is now still impossible to completely prevent the contagion of an infectious disease. PA1 (1) The operation for spraying the counter-die of an impression material with an antiseptic solution by means of spray equipment filled therewith is prone to slip from memory, since it is not included in the essential steps of preparing a gypsum model by casting gypsum on that counter-die. PA1 (2) Spraying of an antiseptic solution does not assure any sufficient disinfecting effect, since the counter-die of an impression material is only washed with water with the lapse of a short time after it has been sprayed with an antiseptic solution by means of spray equipment filled therewith. PA1 (3) It is difficult to achieve effective disinfection, since an antiseptic solution is neither evenly sprayed over the entire surface of the counter-die of an impression material nor sufficiently sprayed on an undercut portion, etc.
To spray the counter-die of an impression material with an antiseptic solution by means of spray equipment filled therewith is a simple procedure, but has the following demerits.